CVE-2021-26871

Local privilege escalation via undisclosed WalletService flaw

Published Mar 11, 2021 · Updated Aug 19, 2026

Elevation of privilege in Microsoft Windows 10 WalletService allows local users with low privileges to gain elevated access. Microsoft has not published the vulnerable code path or the incorrect operation performed by WalletService on attacker-controlled input. Exploitation requires local low-privilege access and no user interaction; success compromises confidentiality, integrity, and availability at elevated privilege.

CVSS severity7.8
High
EPSS probability1.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Elevation of privilege in Microsoft Windows 10 WalletService allows local users with low privileges to gain elevated access. Microsoft has not published the vulnerable code path or the incorrect operation performed by WalletService on attacker-controlled input. Exploitation requires local low-privilege access and no user interaction; success compromises confidentiality, integrity, and availability at elevated privilege.

The record

CVE
CVE-2021-26871
Published
Mar 11, 2021
Updated
Aug 19, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.10240.0 <10.0.10240.18874

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.18874
Microsoft · Windows 10 Version 1909version=10.0.0 <10.0.18363.1440
Microsoft · Windows 10 Version 1803version=10.0.0 <10.0.17134.2087
Microsoft · Windows 10 Version 20H2version=10.0.0 <10.0.19043.867
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.4283
Microsoft · Windows 10 Version 2004version=10.0.0 <10.0.19043.867
Microsoft · Windows 10 Version 1809version=10.0.0 <10.0.17763.1817; version=10.0.17763.0 <10.0.17763.1817

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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